* Adds `bind`, `isFinite`, and `isNumber` utility functions from lodash.
* Use new util funtions instead of lodash throughout the codebase.
* Remove lodash from vendor builds.
closes#2893, issue #2850, issue #2856
- this is a stable, but quick and dirty validations layer for the time constraints
- this could be replaced with a unified server/client layer later. the infrastructure is there.
- create a validation engine mixin to match validators with models
- override the save method in the mixin to perform validations first
- create a post validator
- fixup calls to .save() to make sure they catch errors properly
